公开(公告)号：US20190175944A1

公开(公告)日：2019-06-13

申请号：US16212078

申请日：2018-12-06

Applicant: Elekta Limited

Inventor： Stephen Towe ,  Begoña Vivas-Maiques ,  Janusz Harasimowicz ,  David Reberts

IPC: A61N5/10

Abstract: A method of determining the shape of a radiation beam of a radiotherapy system at a treatment position, the system comprising a radiation source and a multi-leaf collimator disposed between the radiation source and the treatment position. The multi-leaf collimator includes an array of moveable leaves positioned to intersect and block parts of the radiation beam to define the shape of the radiation beam at the treatment position. The leaves of a group are aligned such that the planes of the leaves in that group converge at a point displaced laterally from the radiation source. The method includes, for each leaf in the array positioned to intersect the radiation beam, determining a projected width with respect to the radiation beam, the projected width being greater than the thickness of the respective leaf, and using the projected leaf width to determine the shape of the radiation beam at the treatment position.